Game machine

ABSTRACT

Herein disclosed is a game machine ( 1 ) which comprises: storage means constituted by a main control circuit ( 71 ) for storing therein a BET-1 winning probability table for associating a winning probability of winning a predetermined winning prize with each of a regular playing state and an RB playing state under the condition that the number of medals to be betted is one, a BET-3 winning probability table for associating a winning probability of winning a predetermined winning prize with each of a regular playing state and an RB playing state under the condition that the number of medals to be betted is three, and a BET-selection winning probability table for associating a winning probability of winning a predetermined winning prize with each of the regular playing state and the RB playing state under the condition that the number of medals to be betted is three in the regular playing state and the one in the RB playing state; and internal lottery means constituted by the main control circuit ( 71 ) for selecting a random number after randomly sampling the random number to perform an internal lottery based on the random number with reference to a winning probability associated with one of the BET-1 or BET-3 winning probability table and the BET-selection winning probability table.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a game machine enabling to select a betting condition including a playing value to be betted on a game in a predetermined playing state.

2. Description of the Related Art

Up until now, there have been proposed a wide variety of conventional game machines. One typical example of the conventional game machine comprises a plurality of annular rotation reels each of which is provided with different symbol marks on its outer surface and rotatable to have the different symbol marks shifted on respective columns of the rotation reels, a main control circuit for deciding an internal winning prize in a game and controlling the rotation reels to have the different symbol marks displayed on the basis of the internal winning prize decided by the main control circuit and the stop operation carried out by a game player, and a liquid crystal display (hereinlater simply referred to as “LCD”) unit for displaying entertaining images related to the game (see, for example, the following patent publication 1). The conventional game machine thus constructed is adapted to have the LCD unit display information on a stop operation procedure required for the game player to carry out to stop the symbol marks from shifting in the event that a predetermined internal winning prize is won. In one example, the conventional game machine is adapted to have the display unit display the stop operation procedure information for a predetermined service time period to assist the game player in winning a real prize after the internal winning prize is decided.

[Patent Publication 1]

Japanese Patent Laid-Open Publication No. 2003-62172 (see page 3, right upper column, FIGS. 27, 27, and 28, etc.)

The above conventional game machine still leaves for improvement in selectively changing the number of medals to be betted on a game in a predetermined playing state to diversify the game although the above conventional game machine realizes a fun in the game during the service time period.

The present invention is made for the purpose of overcoming the conventional problems, and it is, therefore, an object of the present invention to provide a game machine which enables a game player to diversify the game with the playing state and the playing value to be betted on the game.

SUMMARY OF THE INVENTION

In accordance with an aspect of the present invention, there is provided a game machine according to the present invention (for example, a slot machine 1 shown in FIG. 1), comprising: storage means (for example, a main control circuit 71 shown in FIG. 7) for storing therein a first winning probability table (for example, a BET-1 winning probability table shown in FIG. 3, and a BET-3 winning probability table shown in FIG. 4) for associating a winning probability of winning a predetermined winning prize (for example, a small BELL prize, a Replay prize, and a RB prize) with each of a plurality of playing states (for example, a regular playing state and a RB playing state) under the condition that a playing value (for example, the number of medals) to be betted on a game is constant, and a second winning probability table (for example, a BET-selection winning probability table shown in FIG. 5) for associating a winning probability of winning a predetermined winning prize with each of a plurality of playing states under the condition that a playing value to be betted on the game is selectively specified in accordance with each of said playing states; and internal lottery means (for example, a main control circuit 71 shown in FIG. 7) for selecting a random number after randomly sampling said random number at a predetermined timing to perform an internal lottery based on said random number with reference to a winning probability associated with one of said first winning probability table and said second winning probability table.

The aforementioned game machine (for example a slot machine 1 shown in FIG. 1) may further comprise selecting means (for example, a 1-BET switch 11, a selection-BET switch 12, a 3-BET switch 13, and a main control circuit 71) for selecting a winning probability table from among said first winning probability table and said second winning probability table.

The game machine according to the present invention thus constructed enables the game player to change the winning probability in accordance with the playing value to be betted on one game even under the condition of the same playing state and the same internal winning state, and thus diversify the game, resulting from the fact that the game machine according to the present invention comprises storage means for storing therein a first winning probability table for associating a winning probability of winning a predetermined winning prize with each of a plurality of playing states under the condition that a playing value to be betted on the game is constant, and a second winning probability table for associating a winning probability of winning a predetermined winning prize with each of a plurality of playing states under the condition that a playing value to be betted on the game is selectively specified in accordance with each of said playing states; and internal lottery means for selecting a random number after randomly sampling said random number to perform an internal lottery based on said random number with reference to a winning probability associated with one of said first winning probability table and said second winning probability table.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of a game machine according to the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic perspective view showing a preferred embodiment of a slot machine according to the present invention;

FIG. 2 is a view explaining a preferred embodiment of a relationship table indicative of a relationship between a combination of symbol marks corresponding to a winning prize, and the number of medals awarded;

FIG. 3 is a view explaining a preferred embodiment of a winning probability table to be used under the condition that one medal is betted;

FIG. 4 is a view explaining a preferred embodiment of a winning probability table to be used under the condition that three medals are betted;

FIG. 5 is a view explaining a preferred embodiment of a winning probability table to be used under the condition that the number of medals is selectively betted;

FIG. 6 is a view explaining a preferred embodiment of a final winning selecting table;

FIG. 7 is a schematic block showing a preferred embodiment of a main control circuit;

FIG. 8 is a flowchart showing a preferred embodiment of a reset interrupt process; and

FIG. 9 is a flowchart showing a preferred embodiment of a periodic interrupt process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the game machine according to the present invention will now be described in detail in accordance with the accompanying drawings.

FIG. 1 is a schematic perspective view showing a preferred embodiment of a game machine according to the present invention. The game machine is exemplified by a so-called “slot machine 1”. The slot machine 1 allows a game player to bet on a game a game medium in addition to coins, medals, game balls, tokens, and the like. The game medium includes a card having stored therein information on a playing value assigned to or to be assigned to the game player. It is hereinlater assumed that the slot machine 1 allows the game player to bet medals on a game for the purpose of simplifying the description.

The slot machine 1 is as a whole constituted by a housing 2. The housing 2 has a front panel partially constituted by a display unit 2 a extending substantially perpendicular to the ground. The display unit 2 a includes in the center thereof display windows 4L, 4C, and 4R each in the form of a vertically long rectangle shape. The display windows 4L, 4C, and 4R collectively have a plurality of prize-winning lines including a center prize-winning line 8 c horizontally extending over the center of the windows 4L, 4C, and 4R; a pair of upper and lower prize-winning lines 8 b and 8 d disposed on upper and lower sides of the center prize-winning line 8 c and extending in parallel relationship with the center prize-winning line 8 c; and a pair of cross-up and cross-down prize-winning lines 8 a and 8 e crossed at oblique angles and traversing the prize-winning lines 8 b, 8 c, and 8 d, respectively. One, three, or five of the prize-winning lines are made effective in betting when a 1-BET switch 11, a selection BET switch 12, or a 3-BET switch 13 is operated by the game player or a medal is inserted into a medal insertion slot 22. The medal insertion slot 22, the 1-BET switch 11, the selection-BET switch 12, and the 3-BET switch 13 will be described later. BET lamps 9 a, 9 b, and 9 c are designed to light up and off to indicate which of the prize-winning lines 8 a, 8 b, 8 c, 8 d, and 8 e are made effective in betting. The BET lamps 9 a, 9 b, and 9 c will be described later.

The prize-winning lines 8 a, 8 b, 8 c, 8 d, and 8 e play an important role in judging whether or not a prize is won. In the concrete, a winning prize is won as a result of the fact that a symbol mark corresponding to a predetermined winning prize, for example, a small winning prize “Bell”, which will be described later, is stopped and displayed on a predetermined position of the prize-winning line, for example, a middle column of the display window 4L in the case that a BET number, which will be described later, is “three”, or a combination of symbol marks corresponding to a predetermined winning prize are stopped and displayed on a predetermined position of one of the prize-winning lines.

The slot machine 1 further comprises three rotation reels 3L, 3C, and 3R rotatable and juxtaposed to one another inside of the housing 2. Each of the rotation reels 3L, 3C, and 3R has a peripheral surface having thereon various kinds of symbol marks arranged in a row at a predetermined interval. Each of the symbol marks arranged on the rotation reels are visible to and seen by the game player through the display windows 4L, 4C, and 4R. Each of the rotation reels is rotatable at a predetermined speed, for example 80 revolutions per minute.

The slot machine 1 further comprises a 1-BET lamp 9 a, a selection BET lamp 9 b, a 3-BET lamp 9 c, an information display unit 18, and an arrow key 24 on the left side of the display windows 4L, 4C, and 4R Each of the 1-BET lamp 9 a, the selection BET lamp 9 b, and the 3-BET lamp 9 c is lighted up in accordance with the number of medals to be betted on a game, hereinlater simply referred to as “BET number”.

The 1-BET lamp 9 a is operative to light up when one prize-winning line is made effective in betting (one effective line is specified) under the condition that the BET number is equal to “1”. The selection-BET lamp 9 b is operative to light up when all (five) of the prize-winning lines are made effective in betting (five effective lines are specified) under the condition that the BET number is equal to “3” in a regular playing state, or when one prize-winning line is made effective in betting (one effective line is specified) under the condition that the BET number is equal to “1” in a regular bonus, hereinlater simply referred to as “RB”, playing state. The 3-BET lamp 9 c is operative to light up when all (five) of the prize-winning lines are made effective in betting (five effective lines are specified) under the condition that the BET number is equal to “3”. The information display unit 18 is constituted by 17 segments of LED (light emitting diodes) and designed to display the number of medals credited to the game player, the number of medals to be paid out when a prize is won, and the like. The arrow key 24 is adapted to allow the game player to operate a liquid crystal display (hereinlater simply referred to as “LCD”) unit 5, which will be described later, to carry out various setting operations.

The slot machine 1 further comprises a middle base portion 10 horizontally protruding from the front panel below the display windows 4L, 4C, and 4R, and a LCD unit 5 intervening between the middle base portion 10 and the display windows 4L, 4C, and 4R. The LCD unit 5 is formed with a display screen Sa to have information related to a game displayed thereon.

The slot machine 1 further comprises a medal insertion slot 22 on the right side of the LCD unit 5, and a 1-BET switch 11, a selection BET switch 12, and a 3-BET switch 13 on the left side of the liquid display unit 5. The 1-BET switch 11, the selection BET switch 12, and the 3-BET switch 13 are adapted to allow the game player to determine the number of medals to be betted on one game. When the 1-BET switch 11 is once pushed by the game player, one medal credited to the game player is betted for playing a game regardless of its playing state. When the 3-BET switch 13 is once pushed by the game player, three medals credited to the game player are betted for playing the game regardless of its playing state. When, on the other hand, the selection BET switch 12 is once pushed by the game player, three medals credited to the game player are betted for playing the game in the regular playing state, or one medal credited to the game player is betted for playing the game in the RB playing state. Further, corresponding one or more prize-winning lines are made effective in betting when the 1-BET switch 11, the selection BET-switch 12, or the 3-BET switch 13 is operated by the game player, as described hereinearlier.

The slot machine 1 further comprises a C/P switch 14 on the left front side of the middle base portion 10, a medal payout opening 15 and a medal receiving saucer 16 on the left lower portion of the housing 2. The C/P switch 14 is adapted to switch selectively one of two modes including a credit mode having a medal won by the game player credited to the game player and a payout mode having a medal won by the game player paid out to the other. When the slot machine 1 is operated in, for example, the payout mode switched by the he C/P switch 14, the medals won by the game player are fallen by their own weight through the medal payout opening 15 and received in the medal receiving saucer 16.

The slot machine 1 further comprises a start lever 6 on the left side of the C/P switch 14. The start lever 6 is pivotable at a variable inclination angle to start shifting the symbol marks respectively visible to and seen by the game player through the display windows 4L, 4C, and 4R.

The slot machine 1 further comprises a plurality of stop buttons 7L, 7C, and 7R on the middle front side of the middle base portion 10 below the LCD unit 5. The stop buttons 7L, 7C, and 7R are adapted to allow the game player to respectively stop the rotation reels 3L, 3C, and 3R from rotating. The slot machine 1 further comprises speaker units 21L and 21R respectively on the upper left side and upper right side of the medal receiving saucer 16.

In the present embodiment, it is assumed that one game (referred to as “unit game”) is started when the start lever 6 is operated and terminated when all of the rotation reels 3L, 3C, and 3R are stopped from rotating. Further, it is assumed that the maximum value of a “shifting range” is set at four during a game. Here, the shifting rage is intended to mean the number of symbol marks to be shifted and displayed through the display window 4L, 4C, or 4R for a time period starting from the operation of the stop button 7L, 7C, or 7R is detected until the rotation reel 3L, 3C, or 3R is stopped from rotating. This means that the shifting rage indicates the number of symbol marks shifted (the shift distance of the symbol mark) on the rotation reel 3L, 3C, or 3R for the time period starting from the operation of the stop button 7L, 7C, or 7R is detected until the respective rotation reel 3L, 3C, or 3R is stopped from rotating. In the concrete, the number of shifting range is equal to the number of symbol marks on each of the rotation reels 3L, 3C, and 3R whose center portions have passed over a predetermined effective prize-winning line such as, for example, the center prize-winning line 8 c for the time period starting from the operations of the stop buttons 7L, 7C, and 7R are detected until the respective rotation reels 3L, 3C, and 3R are stopped from rotating.

Each of the rotation reels 3L, 3C, and 3R is provided with a row of twenty-one symbol marks on its outer surface. Each of the symbol marks is assigned to a code number selected from among numbers “00” to “20”, and associated with a data table stored in a ROM 32 (shown in FIG. 7), which will be described later. On each of the rotation reels 3L, 3C, and 3R are provided combinations of symbol marks such as, for example, “BELL”, “Replay”, and “BAR”, not shown. In the present embodiment, it is assumed that on the rotation reels 3L, 3C, and 3R, are provided combinations of symbol marks respectively corresponding to a RB prize, a Replay prize, a small Bell prize, and Losing.

Further, in the present embodiment, the operation of stopping the rotation reels while all of the rotation reels are rotating is called a “first stop operation”, the operation of stopping the rotation reels performed after the first stop operation is carried out is called a “second stop operation”, and the operation of stopping the rotation reels performed after the second stop operation is carried out is called a “third stop operation”. It is herein assumed that the maximum shifting range is set at “one” for the rotation reel to be stopped as a result of the first stop operation while, on the other hand, the maximum shifting range is, in principle, set at “0” for the rotation reel to be stopped as a result of the second stop operation or the third stop operation.

FIG. 2 is a view explaining a relationship table to be used in the present embodiment, and indicative of a relationship between a combination of symbol marks corresponding to a winning prize and the number of medals awarded.

The RB prize is won when three symbol marks each indicative of BAR, viz., BAR-BAR-BAR, are aligned on the effective prize-winning line. The number of medals to be paid out for the RB prize is “104” under the condition that the BET number is set at “1” in a regular playing state, “69.68” under the condition that the BET number is set at “3” in a regular playing state, and “104” under the condition that the BET number is set at a selection BET in a regular playing state as clearly seen from FIG. 2.

The small Bell prize is won when three symbol marks each indicative of Bell, viz., Bell-Bell-Bell, are aligned on the effective prize-winning line. The number of medals to be paid out for the small Bell prize is “15” regardless of the BET number and the playing state as clearly seen from FIG. 2.

The Replay prize is won when three symbol marks each indicative of Replay, viz., Replay-Replay-Replay, are aligned on the effective prize-winning line. The number of medals to be paid out for the RB prize is “1” under the condition that the BET number is set at “1”, “3” under the condition that the BET number is set at “3”, and “3” under the condition that the BET number is set at a selection BET as clearly seen from FIG. 2. When the Replay prize is won, medals equal in the number to the medals inserted and betted on the previous game are automatically inserted. This means that the Replay prize makes it possible for the game player to replay the game without inserting additional medals.

FIG. 3 is a view explaining a BET-1 winning probability table to be used in the present embodiment under the condition that the BET number is set at one, viz., “1”.

As clearly seen from the BET-1 winning probability table shown in FIG. 3, the probability of winning the RB prize is equal to “1/32.77” in the regular playing state, the probability of winning the small BELL prize is equal to “1/23.08” in the regular playing state, the probability of winning the Replay prize is equal to “1/5.46” in the regular playing state, and the probability of losing the game is equal to “1/1.23” in the regular playing state. Further, the probability of winning the RB prize is equal to “0” in the RB playing state, the probability of winning the small BELL prize is equal to “16383/16384” in the RB playing state, the probability of winning the Replay prize is equal to “0” in the RB playing state, and the probability of losing the game is equal to “1/16384” in the RB playing state as clearly seen from FIG. 3. Here, the number of medals expected to be obtained in the regular playing state is equal to “0” and the number of medals expected to be obtained in the RB playing state is equal to “13” in the case that the BET-1 winning probability table shown in FIG. 3 is applied.

FIG. 4 is a view explaining a BET-3 winning probability table to be used in the present embodiment under the condition that the BET number is set at three, viz., “3”.

As clearly seen from the BET-3 winning probability table shown in FIG. 4, the probability of winning the RB prize is equal to “1/13.54” in the regular playing state, the probability of winning the small BELL prize is equal to “1/2.38” in the regular playing state, the probability of winning the Replay prize is equal to “1/5.46” in the regular playing state, and the probability of losing the game is equal to “1/1.98” in the regular playing state. Further, the probability of winning the RB prize is equal to “0” in the RB playing state, the probability of winning the small BELL prize is equal to “1/1.02” in the RB playing state, the probability of winning the Replay prize is equal to “0” in the RB playing state, and the probability of losing the game is equal to “1/42.67” in the RB playing state as clearly seen from FIG. 4. Here, the number of medals expected to be obtained in the regular playing state is equal to “0” and the number of medals expected to be obtained in the RB playing state is equal to “8.71” in the case that the BET-3 winning probability table shown in FIG. 4 is applied.

FIG. 5 is a view explaining a BET-selection winning probability table to be used in the present embodiment under the condition that the BET number is selectively specified.

As clearly seen from the BET-selection winning probability table shown in FIG. 5, the probability of winning the RB prize is equal to “1/13.54” in the regular playing state, the probability of winning the small BELL prize is equal to “1/2.38” in the regular playing state, the probability of winning the Replay prize is equal to “1/5.46” in the regular playing state, and the probability of losing the game is equal to “1/1.98” in the regular playing state. Further, the probability of winning the RB prize is equal to “0” in the RB playing state, the probability of winning the small BELL prize is equal to “16383/16384” in the RB playing state, the probability of winning the Replay prize is equal to “0” in the RB playing state, and the probability of losing the game is equal to “1/16384” in the RB playing state as clearly seen from FIG. 5. Here, the number of medals expected to be obtained in the regular playing state is equal to “2.53” and the number of medals expected to be obtained in the RB playing state is equal to “13” in the case that the BET-selection winning probability table shown in FIG. 5 is applied.

FIG. 6 is a view explaining a final winning prize selecting table to be used in the present embodiment to determine a final winning prize when the rotation reels are stopped.

As best shown in FIG. 6, the final winning prize selecting table shows a probability (selecting probability) of selecting a final winning prize when the rotation reels are stopped for each of internal winning prizes and playing states. The final winning prize is used as information to control the rotation reels 3L, 3C, and 3R to have the rotation reels 3L, 3C, and 3R stop from rotating. This means that the rotation reels 3L, 3C, and 3R are controlled and thus stopped from rotating in such a manner that the symbol marks corresponding to the final winning prize can be shifted and displayed in the display windows 4L, 4C, and 4R when the final winning prize is selected. In addition, the rotation reels 3L, 3C, and 3R are controlled and thus stopped from rotating in such a manner that the symbol marks corresponding to a winning prize other than the final winning prize other are prevented from being stopped and displayed in the display windows 4L, 4C, and 4R when the final winning prize is selected. The final winning prize is determined, in conformance with each of the probabilities shown in FIG. 6, through the steps of randomly sampling a random number from among a predetermined range of random numbers (for example, 0 to 127), subtracting a predetermined lottery number corresponding to the internally winning prize from the random number, judging whether or not the random number thus subtracted is less than zero, and selecting a final winning prize corresponding to the subtracted random number when it is judged that the random number thus subtracted is less than zero.

As shown in FIG. 6, the probability of winning the RB prize as a final winning prize in the regular playing state is equal to “128/128” in the case that the internal winning prize is the RB prize, the probability of winning the small BELL prize as a final winning prize in the regular playing state is equal to “128/128” in the case that the internal winning prize is the small BELL prize. Likewise, the probability of winning the Replay prize as a final winning prize in the regular playing state is equal to “128/128”, the probability of winning the “Ri-chi-me” as a final winning prize in the regular playing state is equal to “0/128”, and the probability of losing the game as a final winning prize in the regular playing state is equal to “0/128” in the case that the internal winning prize is the Replay prize. Likewise, the probability of losing the game as a final winning prize in the regular playing state is equal to “128/128”, and the probability of winning the “Ri-chi-me” as a final winning prize in the regular playing state is equal to “0/128”, in the case that the internal winning prize is losing the game. The “Ri-chi-me” appearing hereinabove is intended to mean that a predetermined combination of symbol marks are stopped and displayed on a predetermined position of the prize-winning line so as to notify the game player that a BB prize or the RB prize is won as the internal winning prize.

Further as clearly seen from FIG. 6, the probability of winning the small BELL prize as a final winning prize in the RB playing state is equal to “128/128” in the case that the internal winning prize is the small BELL prize. Likewise, the probability of winning the Replay prize as a final winning prize in the RB playing state is equal to “64/128”, the probability of winning the “Ri-chi-me” as a final winning prize in the RB playing state is equal to “32/128”, and the probability of losing the game as a final winning prize in the RB playing state is equal to “32/128” in the case that the internal winning prize is the Replay prize. Likewise, the probability of losing the game as a final winning prize in the RB playing state is equal to “64/128”, and the probability of winning the “Ri-chi-me” as a final winning prize in the RB playing state is equal to “64/128”, in the case that the internal winning prize is losing the game. The RB prize cannot be selected as the internal winning prize in the RB playing state as clearly seen from FIGS. 3 through 5.

As shown in FIG. 7, the slot machine 1 further comprises a main control circuit 71 for controlling the game operations performed by the slot machine 1, peripheral devices (actuators) electrically connected with the main control circuit 71, and a secondary control circuit 72 for controlling the operations of the LCD unit 5, the speaker units 21L and 21R, a LED system 101, and a lamp system 102.

The main control circuit 71 comprises, as a primary constituent element, a microcomputer 30 mounted on a circuit board, not shown. The main control circuit 71 further comprises a clock pulse generating circuit 34 for generating a reference clock pulse, a divider 35, and a random number sampling circuit for sampling a random number. The random number sampling circuit is constituted by a random number generating unit 36 for generating a plurality of random numbers and a sampling circuit 37 for sampling a random number generated by the random number generating unit 36 at a predetermined timing. The microcomputer 30 includes a central control unit (hereinlater simply referred to as “CPU”) 31 for executing a predetermined program to perform control operations, a ROM 32, and a RAM 33 collectively constituting storage means according to the present invention, and various types of counters, not shown, including a shortest game time measuring counter, an interrupt counter, and a magnetic counter, all of which will be described later.

The CPU 31 is electrically connected with the clock pulse generating unit 34, the divider 35, the random number generating unit 36, and the sampling circuit 37. While it has been described in the above that the main control circuit 71 comprises the circuit constituted by the random number generating unit 36 and the random number sampling circuit 37 for sampling a random number, it is needless to mention that the CPU 31 may execute a predetermined program to sample a random number. In this case, the random number generating unit 36 and the random number sampling circuit 37 may be omitted from the main control circuit 71, or used as a backup circuit for sampling a random number.

The ROM 32 forming part of the microcomputer 30 has stored therein a plurality of winning probability tables (see FIG. 3, FIG. 4, and FIG. 5) to be used to judge the sampled random number as corresponding to an internal winning prize or not whenever the start lever 6 is operated (to start a game) by the game player, a final winning prize selecting table (see FIG. 6) to be used to determine where to stop the rotation reels in response to the operations of the stop buttons 7L, 7C, and 7R, various kinds of control instructions (viz., commands), and the like. The control instructions includes a stop instruction signal (viz., a rotation reel stop command) to allow the microcomputer 30 to stop each of the rotation reels 3L, 3C, and 3R, a game start instruction signal (viz., a start command), a rotation reel stop permission command, a prize winning command, and the like. In the present embodiment, the secondary control circuit 72 is adapted to transmit no command or information to the main control circuit 71. This means that commands and information are transmitted from the main control circuit 71 to the secondary control circuit 72 in a unilateral way. The RAM 33 forming part of the microcomputer 30 has stored therein various information such as, for example, a rotation reel stop permission flag, a rotation reel stop request flag, a winning prize flag indicative of a winning prize, a rotation reel identifier indicative of a rotation reel to be controlled, and the like.

The main control circuit 71 further comprises a motor driving circuit 39 for controlling a plurality of stepping motors 49L, 49C, and 49R to respectively make the rotation reels 3L, 3C, and 3R rotate or stop, a lamp driving circuit 45 for controlling the BET lamps (the BET lamp 9 a, the selection BET lamp 9 b, and the 3-BET lamp 9 c) to lighting up and off the BET lamps, a display unit driving circuit 48 for controlling the information display unit 18, and a hopper driving circuit 41 for controlling a hopper 40 to make the hopper 40 pay out a predetermined number of medals for a prize. The hopper 40 includes a medal storage section having medals stored therein and a driving section for moving a predetermined number of medals out of the medal storage section.

The CPU 31 includes an input/output port (hereinlater simply referred to as “I/O port”) 38. The CPU 31 is connected with the motor driving circuit 39, the hopper driving circuit 41, the lamp driving circuit 45, and the display unit driving circuit 48 through the I/O port 38. The motor driving circuit 39, the hopper driving circuit 41, the lamp driving circuit 45, and the display unit driving circuit 48 are adapted to receive control signals such as, for example, driving instructions from the CPU 31 to control respective actuators. This means that the microcomputer 30 is operative to control major actuators such as the BET lamps, the information display unit 18, the hopper 40, and the stepping motors 49L, 49C, and 49R.

The slot machine 1 further comprises a start switch 6S for detecting an operation of the start lever 6, a medal sensor 22S for detecting a medal dropped into the medal insertion slot 22, a rotation reel stop signal circuit 46 for generating a stop signal in response to the operation of each of the stop buttons 7L, 7C, and 7R, a rotation reel sensor, not shown, for detecting a rotational position of each of the rotation reels 3L, 3C, and 3R, a rotation reel position detecting circuit 50 for supplying to the CPU 31 a signal indicative of a rotational position of each of the rotation reels 3L, 3C, and 3R in response to a pulse signal transmitted from the rotation reel sensor, a medal counting unit 40S for detecting medals paid out from the hopper 40 to count the number of paid out medals, and a payout completion circuit 51 for outputting a payout completion signal to the CPU 31 when the counted number of the paid out medals exceeds a specified number. The start switch 6S, the 1-BET switch 11, the selection-BET switch 12, the 3-BET switch 13, the C/P switch 14, the medal sensor 22S, the rotation reel stop signal circuit 46, the rotation reel position detecting circuit 50, and the payout completion circuit 51 collectively constitute input signal generating means. The microcomputer 30 is operative to issue control instructions in response to the signals inputted from the input signal generating means.

In FIG. 7, the random number generating unit 36 is operative to generate a plurality of random numbers within a predetermined range of numbers, and the sampling circuit 37 is operative to sample a random number generated by the random number generating unit 36 at a predetermined timing, for example, when the start switch 6S is operated. The CPU 31 is operative to determine an internal winning prize based on the sample number sampled by the sampling circuit 37 and the winning probability tables as described hereinearlier.

After the rotation reels 3L, 3C, and 3R start rotating, the number of driving pulses supplied to each of the stepping motors 49L, 49C, and 49R is counted and stored in a predetermined storage area of the RAM 33. The rotation reel position detecting circuit 50 is operative to receive a reset pulse for every one rotation of each of the rotation reels 3L, 3C, and 3R, and the CPU 31 is operative to input the reset pulse from the rotation reel position detecting circuit 50. The CPU 31 is operative to clear and reset the number of the counted driving pulses stored in the RAM 33 to zero “0” whenever the CPU 31 receives the reset pulse from the rotation reel position detecting circuit 50. This leads to the fact that the counted number of the driving pulses stored in the RAM 33 indicates the rotational position of each of the rotation reels 3L, 3C, and 3R within a range of one rotation.

The ROM 32 has stored therein a symbol mark table, not shown, to associate the symbol marks drawn on the outer surface of each of the rotation reels 3L, 3C, and 3R with the rotational position of each of the rotation reels 3L, 3C, and 3R. On each of the rotation reels 3L, 3C, and 3L is provided a plurality of pitches spaced apart at a constant rotational distance from one after another. Each of the pitches provided on each of the rotation reels 3L, 3C, and 3L is assigned to a code number on the basis of a reference rotational position of each of the rotation reels 3L, 3C, and 3L where the reset pulse is generated. In the symbol mark table, the code number assigned to each of the symbol marks is associated with the code number assigned to each of the pitches provided on each of the rotation reels 3L, 3C, and 3L.

Further, the ROM 32 has stored therein a winning prize-symbol mark combination table, not shown, representative of combinations of symbol marks respectively corresponding to winning prizes, the number of medals to be awarded to the game player for each of the winning prizes, and winning prize judgment codes each corresponding to a winning prize. The winning prize-symbol mark combination table is used to confirm a winning prize when each of the rotation reels 3L, 3C, and 3R is stopped from rotating or after all of the rotation reels 3L, 3C, and 3R are stopped from rotating.

The CPU 31 is operative to transmit a stop control signal (viz., a stop instruction signal) to the motor driving circuit 39 to stop the rotation reels 3L, 3C, and 3R from rotating based on a stop control table, not shown, and an operation signal transmitted from the rotation reel stop signal circuit 46 at a timing when each of the stop buttons 7L, 7C, and 7R is operated by the game player.

When a prize is won, the CPU 31 is operative to transmit a payout instruction signal to the hopper driving circuit 41 to have the hopper 40 pay out a predetermined number of medals. At this time, the medal counting unit 40S is operative to count the number of paid out medals, and the payout completion circuit 51 is operative to output a payout completion signal to the CPU 31 when the counted number of the paid out medals exceeds a specified number. Upon receiving the payout completion signal, the CPU 31 is operative to control the hopper driving circuit 41 to have the hopper 40 stop from paying out a medal, and thus the medal payout operation is terminated.

The control operation of the slot machine 1 thus constructed as previously mentioned will be described hereinlater with reference to FIG. 8 and FIG. 9. It is herein assumed that interrupt processes such as, for example, an interrupt processes carried out when, for example, power is turned on, a random number is updated, and the system is reset, and other periodic interrupt processes are respectively assigned to priority orders and executed in a multiplex way based on the respective priority orders.

The description hereinlater will be directed to the reset interrupt process performed by the main control circuit 71 with reference to FIG. 8.

In step S101, the CPU 31 is operated to initialize the system when the power is turned on (step S101). In the concrete, the CPU 31 is operated to initialize data stored in the RAM 33, communication data, and the like.

Step S101 goes forward to step S102, in which the CPU 31 is operated to erase predetermined data stored in the RAM 33 (step S102) at the time when the previous game is terminated. This means that the CPU 31 may erase data stored in a predetermined storage area (for example, a storage area where the internal winning prize of the previous game is stored) of the RAM 33. In the concrete, the CPU 31 is operated to erase data stored in a writable storage area of the RAM 33 in the previous game, write necessary parameters into the writable storage area of the RAM 33, and specify a start address of a sequence program to be used for the next game.

Step S102 goes forward to step S103, in which the CPU 31 is operated to monitor medal insertion and carry out a start checking process. In the concrete, the CPU 31 is operated to detect the present playing state, and judge whether or not an input signal is received from the medal sensor 22S, or each of the 1-BET switch 11, a selection BET switch 12, and a 3-BET switch 13. Further, the CPU 31 is operated to judge whether or not an operation signal indicative of the operation of the start lever 6 is received from the start switch 6S. When the result of the judgment is in the affirmative “YES” in step S103, step S103 goes forward to step S104, in which the CPU 31 is operated to sample a random number for an internal lottery in the manner as described hereinearlier.

Step S104 goes forward to step S105, in which the CPU 31 is operated to carry out an internal lottery process. In the concrete, the CPU 31 is operated to determine an internal winning prize based on the playing state detected and the input signal received in step S103, the random number sampled in step S104, and one of the BET-1 winning probability table, the BET-3 winning probability table, and the BET-selection winning probability table as described in the above. When, for example, the selection BET switch 12 is operated in the regular playing state, the CPU 31 is operated to judge that three credited medals are betted and carry out the internal lottery based on the random number sampled in step S104 and the BET-selection winning probability table. Further, when, for example, the selection BET switch 12 is operated in the RB playing state, the CPU 31 is operated to judge that one credited medal is betted and carry out the internal lottery based on the random number sampled in step S104 and the BET-selection winning probability table.

Step S105 goes forward to step S106, in which the CPU 31 is operated to carry out a final winning prize determining process. In the concrete, the CPU 31 is operated to determine a final winning prize based on the internal winning prize determined in step S105 and the final winning prize selecting table as described in the above.

Step S106 goes forward to step S107, in which the CPU 31 is operated to carry out a table line selecting process. In the concrete, the CPU 31 is operated to select a prize-winning line (viz., a table line) on which the symbol marks corresponding to the final winning prize determined in step S105 is to be aligned on.

Step 107 goes forward to step S108, in which the CPU 31 is operated to carry out a start command setting process. In the concrete, the CPU 31 is operated to write a start command in a predetermined storage area of the RAM 33. The start command includes information on the internal winning prize, the final winning prize, and the like, and will be transmitted to the secondary control circuit 72.

Step S108 goes forward to step S109, in which the CPU 31 is operated to carry out a shortest game time waiting process. In the concrete, the CPU 31 is operated to nullify any input operation regarding an instruction of starting a game by the game player for a predetermined time (for example, “4.1” seconds) from the game start.

Step S109 goes forward to step S110, in which the CPU 31 is operated to set up the shortest game time measuring counter to start counting a time.

Step S110 goes forward to step S111, in which the CPU 31 is operated to carry out a rotation process of all of the rotation reels 3L, 3C, and 3R. Step S111 goes forward to step S112, in which the CPU 31 is operated to carry out a rotation reel stop permission command setting process. In the concrete, the CPU 31 is operated to write a rotation reel stop permission command in a predetermined storage area of the RAM 33 to set up the rotation reel stop permission flag of each of the rotation reels 3L, 3C, and 3R. The rotation reel stop permission command will be transmitted to the secondary control circuit 72.

Step S112 goes forward to step S113, in which the CPU 31 is operated to judge whether or not the rotation reel stop permission flags of all of the rotation reels 3L, 3C, and 3R are “on”. When the result of the judgment is in the affirmative “YES”, step S113 goes forward to step S114, in which the CPU 31 is operated to judge whether or not any one of the stop buttons 7L, 7C, and 7R is operated. When the result of the judgment is in the affirmative “YES”, step S114 goes forward to step S115, in which the CPU 31 is operated to carry out a shifting range determining process. In the concrete, the CPU 31 is operated to determine the shifting range based on the symbol marks corresponding to the internal winning prize and the current position of the targeted symbol mark.

Step S115 goes forward to step S116, in which the CPU 31 is operated to have the targeted rotation reel 3L, 3C, or 3R rotate for the shifting range in response to the operation of the stop button 7L, 7C, or 7R operated in step S114.

Step S116 goes forward to step S117, in which the CPU 31 is operated to set the rotation stop request flag of the targeted rotation reel 3L, 3C, or 3R to “on”. Step S117 goes forward to step S118, in which the CPU 31 is operated to carry out a rotation reel stop command setting process. In the concrete, the CPU 31 is operated to write a rotation reel stop command in a predetermined storage area of the RAM 33. The rotation reel stop command will be transmitted to the secondary control circuit 72. The secondary control circuit 72 is operated to control, for example, the LCD unit 5 to have the LCD unit 5 display entertaining images related to the game in response to the rotation reel stop command.

Step S118 goes forward to step S119, in which the CPU 31 is operated to judge whether or not all of the rotation reels 3L, 3C, and 3R are stopped from rotating. When the result of the judgment is in the affirmative “YES”, step S119 goes forward to step S120, in which the CPU 31 is operated to write an all-rotation reel stop command in a predetermined storage area of the RAM 33. The all-rotation reel stop command will be transmitted to the secondary control circuit 72.

Step S120 goes forward to step S121, in which the CPU 31 is operated to carry out a winning prize searching process. In the winning prize searching process, the CPU 31 is operated to set a winning prize flag to identify a winning prize (a final winning prize) based on the stop position of the symbol mark to be seen through each of the display windows 4L, 4C, and 4R. In the concrete, the CPU 31 is operated to identify the winning prize based on the code number assigned to each of the symbol marks aligned on the center prize-winning line 8 c and the winning prize-symbol mark combination table.

Step S121 goes forward to step S122, in which the CPU 31 is operated to carry out an incorrect winning prize checking process to judge whether or not the winning prize flag is correct.

Step S122 goes forward to step S123, in which the CPU 31 is operated to carry out a winning prize command setting process. In the concrete, the CPU 31 is operated to write a winning prize command in a predetermined storage area of the RAM 33. The winning prize command will be transmitted to the secondary control circuit 72. The winning prize command includes information on the final winning prize, and the like.

Step S123 goes forward to step S124, in which the CPU 31 is operated to have a predetermined number of medals paid out or credited to the game player.

The description hereinlater will be directed to the periodic interrupt process performed by the main control circuit 71 with reference to FIG. 9. The periodic interrupt process is repeated by the CPU 31 at a predetermined time interval of, for example, 1.173 msec.

In step S201, the CPU 31 is operated to save data in a register to be used during the periodic interrupt process. Step S201 goes forward to step S202, in which the CPU 31 is operated to carry out an input port checking process. In the concrete, the CPU 31 is operated to judge whether or not an input signal is received from the 1-BET switch 11, the selection BET switch 12, and the 3-BET switch 13, and wither or not an operation signal indicative of the operation of the start lever 6 is received from the start switch 6S.

Step S202 goes forward to step S203, in which the CPU 31 is operated to carry out a communication data transmission process. In the concrete, the CPU 31 is operated to transmit the data stored in the predetermined area of the RAM during the reset interrupt process as described earlier with reference to FIG. 8 to the secondary control circuit 72.

Step S203 goes forward to step S204, in which the CPU 31 is operated to increment an interrupt counter by one, viz., “1”. Step S204 goes forward to step S205, in which the CPU 31 is operated to judge whether or not the count value of the interrupt counter is an even number. When the result of the judgment is in the affirmative “YES”, step S205 goes forward to step S206. When, on the other hand, the result of the judgment is in the negative “NO”, step S205 goes forward to step S207.

In step S206, the CPU 31 is operated to carry out a 7SEG drive control process. In the control, the CPU 31 is operated to have the information display unit 18 display the number of medals credited to the game player, the number of medals to be paid out when a prize is won, and the like.

In step S207 to step 212, the CPU 31 is operated to carry out a rotation reel control process after setting information on the targeted rotation reel as a rotation reel identifier. This means that the CPU 31 is operated to set information on the left rotation reel 3L, information on the center rotation reel 3C, and information on the right rotation reel 3R as the rotation reel identifier one after another to control the motor driving circuit 39 to have the rotation reels 3L, 3C, and 3R selectively rotated and stopped. Step S212 goes forward to step S213, in which the CPU 31 is operated to decrement the various types of counters related to each of the rotation reels 3L, 3C, and 3R.

Step S213 goes forward to step S214, in which the CPU 31 is operated to carry out a magnetic counter control process. In the concrete, the CPU 31 is operated to calculate the number of medals appropriately inserted from the medal insertion slot 22. Step S214 goes forward to step S215, in which the CPU 31 is operated to return the data saved in step S201 to the register.

As will be seen from the foregoing description, it is to be understood that the present embodiment of the slot machine 1 according to the present invention, makes it possible for the game player to change the number of medals expected to be obtained in accordance with the playing value to be betted on one game even under the condition of the same playing state and the same internal winning state, and thus diversify the game, resulting from the fact that the slot machine 1 comprises storage means constituted by the main control circuit 71 for storing therein the BET-selection winning probability table for associating a winning probability of winning a predetermined winning prize with each of regular playing state and the RB playing state under the condition that the BET number is set at one, viz., “1” in the regular playing state and the BET number is set at three, viz., “3” in the RB playing state, in addition to the BET-1 winning probability table for associating a winning probability of winning a predetermined winning prize with each of the regular playing state and the RB playing state under the condition that the BET number is set at one, viz., “1”, and the BET-3 winning probability table for associating a winning probability of winning a predetermined winning prize with each of the regular playing state and the RB playing state under the condition that the BET number is set at three, viz., “3”, and internal lottery means constituted by the main control circuit 71 for selecting a random number after randomly sampling the random number to perform an internal lottery based on the random number with reference to a winning probability selectively associated with one of the BET-1 winning probability table, the BET-3 winning probability table, and the BET-selection winning probability table. Especially, the present embodiment of the slot machine 1 according to the present invention may enhance the fun of the game, resulting from the fact that the number of medals expected to be obtained in the regular playing state with three medals to be betted in the case that the BET-selection winning probability table is applied is higher than the number of medals expected to be obtained in the case that the BET-selection winning probability table or the BET-3 winning probability table is applied.

Further, the present embodiment of the slot machine 1 according to the present invention makes it possible for the game player to diversify the game by his or her operation, resulting from the fact that the slot machine 1 further comprises selecting means constituted by a 1-BET switch 11, a selection BET switch 12, a 3-BET switch 13, and the main control circuit 71 for selecting a winning probability table from among the BET-1 winning probability table, the BET-3 winning probability table, the BET-selection winning probability table. Especially, the present embodiment of the slot machine 1 according to the present invention may enhance the fun of the game, resulting from the fact that the game player can actively change the number of medals to be betted during the RB playing state.

In the present embodiment, “a reference expected value in a first playing state” under the condition that a first playing value is betted is defined as a first expected value, and “a reference expected value in the first playing state” under the condition that a second playing value is betted is defined as a second expected value. Further, “a reference expected value in a second playing state” under the condition that the first playing value is betted is defined as a third expected value, and “a reference expected value in the second playing state” under the condition that the second playing value is betted is defined as a fourth expected value. Here, the first playing state (for example, regular playing state) is different from the second playing state (for example, RB playing state), and the first playing value (for example, three medals) is different from the second playing value (for example, one medal). It is assumed that the first expected value is greater in a reference expected value than the second expected value, and the third expected value is less in a reference expected value than the fourth expected value. Moreover, the reference expected value is intended to mean a playing value expected to be paid out to the game player in the unit game (viz., the number of medals expected to be obtained in one game). Alternatively, the reference expected value may mean a so-called expected value of a difference calculated by subtracting a playing value that the game player has invested in a unit game from the playing value expected to be paid out to the game player in the unit game. In this case, the slot machine 1 thus constructed can provide diversified ball shooting functions and thus various funs of games, thereby reducing a risk of making the game player feel bored.

While there has been described in the present embodiment about the fact that the regular playing state is applied to the first playing game state and the RB playing state is applied to the second playing state, the present invention is not limited to the regular and the RB playing states or the first and second playing states, and it is needless to mention that other playing states may be applied to the present invention. For example, in addition to the aforementioned playing states, “a reference expected value in the first playing state” under the condition that a third playing value is betted may be defined as a fifth expected value, “a reference expected value in the second playing state” under the condition that the third playing value is betted may be defined as a sixth expected value, “a reference expected value in a third playing state” under the condition that the first playing value is betted may be defined as a seventh expected value, “a reference expected value in the third playing state” under the condition that the second playing value is betted may defined as an eighth expected value, and “a reference expected value in the third playing state” under the condition that the third playing value is betted may defined as a ninth expected value. In this case, the respective playing states, playing values, and expected values may be defined as follows.

This means that the first playing state (for example, regular playing state), the second playing state (RB playing state), and the third playing state (for example, BB regular playing state) may be different from one another, and the first playing value (for example, “three” medal), the second playing value (for example, “one medal”), and the third playing values (for example, “two medals”) may be different from one another. Further, the first expected value may be greater in a reference expected value than each of the second expected value and the fifth expected value, the fourth expected value may be greater in a reference expected value than each of the three expected value and the sixth expected value, and the ninth expected value may be greater in a reference expected value than each of the seventh expected value and the eighth expected value. In this case, the slot machine 1 thus constructed can provide diversified ball shooting functions. Here, the BB regular playing state is intended to mean a playing state in which a probability of winning the RB prize is higher than in regular playing sate.

While there has been described in the present embodiment about the fact that three medals are betted for playing the game in the regular playing state, and one medal is betted for playing the game in the RB playing state when the selection BET switch 12 is pushed down by the game player, the same effect may still be obtained in the case that, for example, the LCD unit 5 is designed to display an image suggesting that the number of medals expected to be obtain is increased in a predetermined playing state when the selection BET switch 12 is operated by the game player.

While there has been described in the present embodiment about the fact that three medals are betted for playing the game in the regular playing state, and one medal is betted for playing the game in the RB playing state when the selection BET switch 12 is pushed down by the game player, the same effect may still be obtained in the case that, for example, the slot machine 1 may comprise, in addition to the aforementioned 1-BET switch 11, a maximum BET switch (i.e., the selection BET switch 12) for allowing the game player to bet three medals on a game in the regular playing state and bet one medal on a game in the RB playing state, and set/release switch for selectively assuming one of an ON state having the maximum BET switch allow the game player to bet three medals in the regular playing state and one medal in the RB playing state, and an OFF state having the maximum BET switch allow the game player to bet three medals regardless of the playing state. 

1. A game machine, comprising: storage means for storing therein a first winning probability table for associating a winning probability of winning a predetermined winning prize with each of a plurality of playing states under the condition that a playing value to be betted is constant, and a second winning probability table for associating a winning probability of winning a predetermined winning prize with each of a plurality of playing states under the condition that a playing value to be betted is selectively specified in accordance with each of said playing states; and internal lottery means for selecting a random number after randomly sampling said random number to perform an internal lottery based on said random number with reference to a winning probability associated with one of said first winning probability table and said second winning probability table.
 2. A game machine as set forth in claim 1, which further comprises: selecting means for selecting a winning probability table from among said first winning probability table and said second winning probability table. 